Preheat oven to 350 degrees.
In a large bowl, add cake mix, pudding mix, eggs, vegetable oil, milk and vanilla extract. Using a hand mixer or stand mixer, mix until all ingredients are well combined.
Spray bundtlette pan or full size bundt pan with baking release spray. Use a pastry brush to make sure each cavity is well coated.
Add cake batter to the pan and top with Biscoff cookie pieces.
Bake mini bundt cakes for 20 to 25 minutes or until a toothpick comes out clean.
Allow cakes to cool on a wire rack completely.
Using a hand or standing mixer, add butter, cream cheese, and powdered sugar and mix well until well combined.
Pipe cream cheese frosting on to cakes.
Microwave two tablespoons of Biscoff cookie butter until slightly melted.
Drizzle cookie butter on top of cakes.
Top with halved cookie into center of the cake.